Clutch mechanism



Filed Sept. 50, 1932 4 sheets -sheet l lV/T/VEISSES L I w. M. EMERY CLUTCH macrmmsu 4 Sheets-Sheet 2 Filed Sept. 30, 1932 H 3 INVENTOR @Z/LW/Kika i.

April 1935.v w. M. EME RY 1,997,682

CLUTCH MECHANISM Filed Sept. 30, 1952 4 Sheets-Sheet 3 v INVENTOR lv/r/vfssia 6%. BY l v April 16, 1935.

w. M. EMER-Y CLUTCH MECHANISM Filed sept. 30, 1932 4 Sheets-Sheet 4 m T N E V m ATTORNEY Patented Apr. l6, 1935 CLUTCH MECHANISM William M. Emery, Lansdowne, Pm, assignor to Westinghouse Electric & Manufacturing Company, a corporation of Pennsylvania Application September 30, 1932, Serial No. 685,521

BClaims.

My invention relates to clutches and is herein illustrated by showing its application to an ironing machine.

An object is to provide a clutch mechanism 5 suitable for control by an altemating-current electromagnet.

Another object is to provide a clutch in which the energy required to control it is reduced to a minimum and is not variable with the load transmitted by the clutch.

Another object is to provide a clutch in which the driven member is entirely free when disengaged.

Another object is to provide a reliable and positive clutch operative at high speeds.

A final object is to improve the control and clutch mechanisms on ironing machines.

. In the drawings:

Figure 1 is an elevational view of the righthandend of an ironing machine with the roll at rlelst instable equilibrium and separated from the s cc,

Fig. 2 is a similar view with the roll moved to the shoe,

Fig. 3 is a view in longitudinal section, ing the interior of the roll,

Fig. 4 is a fragmentary view in end elevation, showing the clutch,

Fig. 5 is a longitudinal sectional view of the clutch and gearbox,

Fig. 6 is a perspective view of the motor and clutch parts,

Fig. '7 is an exploded perspective view the individual parts of the clutch, and

Figs. 8 and 9 are fragmentary views, in section,

25 showshowing showing modified forms of manual control means for the clutch.

Applicant believes that his clutch invention, per se, as a machine element, is subject to many useful applications and the use herein shown should be considered but a random selection from its broad field of application.

For this reason the applicant will describe the structure of the ironing machine without extended explanation. Full details and explanation are contained in his copending applications Serial No. 632,498, filed September 10, 1932, and Serial No. 630,351, filed August 25,1932. y

In Figs. 1, 2 and 3 is shown an ironer including a base l2, an upstanding support -l3 attached thereto for a shoe l4 adapted to be heated. On the rear of the base is resiliently mounted a support l and fixed relative thereto is a yoke having yoke ends l8 and lSa, which support pivots [8 from which swing arms IS, in which are fixedly mounted spindles and 20' on which a motor 2| and a gearbox 22 are fixedly mounted. A power unit structure is thus formed, each part fixed relative to the others and consisting of the parts is,

20, 20', 2| and 22 just described. A padded roll 5 structure 23 including a padded metal cylinder and three spiders, is rotatably mounted on spindles 20 and 20'. The power unit structure and the roll structure are normally free to swing on pivots l8.

Motor 2 l, as shown in Fig. 3, includes a housing 24,- a stator 25, fixed to said housing by screws, belts or by welding, and a rotor 26 with a shaft on which is cut a pinion 21 which extends into the gearbox 22.

It should be noted that the stator in this ironer is not bolted rigidly to some fixed support, as it is in most motor applications, but is free to turn orswing on pivots l8 towards and away from the shoe as a result of reactive forces associated with. 20 it On the left end of the roll is shown a brake band 3| (see Fig. 3) which acts against the rotation of roll 23 being held itself against rotation by an operative connection (not shown) with lefthand yoke end l6.

The gear reduction mechanism consists generally of three spur gear reductions, two in the gearbox and one outside, the latter consisting of a pinion 20 and an internal gear 29, which gear 30 is fixedly attached to the 'roll structure. The clutch is located between the first and second reductions.

Referring now to the clutch mechanism, Figs.

4, 5, 6 and 7 show a gear housing}! on which is mounted a small electromagnet 40 which includes coil 4|, a stationary yoke 42, and a reciprocating armature 43 having integral therewith a projection 44, normally moved into the gearbox 22 by a spring 45' shown only in Fig. 5, and 40 constituting an obstacle.

Motor pinion 21, as shown in Fig. 4, meshes with gear 46 having four internal ratchet teeth 41. Gear 46 is loosely mounted on a shaft 48 which is loosely mounted in bearings 49 in gearbox 22. 45 A supporting member 50 of substantially 'cam shape is rigidly secured to shaft 48 intermediate its ends and is provided with a recess 50a. in its surface and with an opening 50b therethrough as well as with a tubular member 50c also extend- 50 ing therethrough, all for purposes to be hereinafter set forth.

A drag or friction means 5| in the form of a fiat disc is loosely anchored relatively to member 50 by a laterally-extending integral lug 52 fitting 55 loosely in opening 58b. Disc 5| is pressed into a recess in gear by a spring 58 one end of which abuts against member 58.

A ratchet wheel 55 having four external ratchet teeth and a pinion 55 integral therewith is also loosely mounted on shaft 48 at one side of the cam-shaped member 58.

A curved lever arm 58 having a pawl 51 thereon intermediate its ends is pivotally mounted at one end thereof on one side of member 58 on tubular member 580. A second curved lever arm 58 having a pawl 58 at one end thereof is pivotally mounted on the other end of tube 580 at the other side of member 58. A light double torsional spring 5| provides the small pressure necessary to keep pawls 51 and 58 normally in engagement with the teeth of ratchets 41 and 55 respectively. The arms 58 and 58 have projections 58a and 88a at one end thereof adapted to be engaged by obstacle 44 as will be hereinafter described.

A machine bolt 52 extends through openings in arms 53 and 58, through tube 580 and through the turns of spring 5| to hold these members in proper assembled and operative positions, a nut 83 being provided to hold the bolt 52 when once assembled. While a machine bolt has been shown, it is possible to use a rivet.

When rotor pinion 21 rotates in normal operation and coil 4| is energized and the obstacle 44 withdrawn by the magnet, then all the parts shown in Fig. 7 revolve as a unit. When the magnet 48 is deenergized and spring 45 moves the projection or obstacle 44 into the path of pawl levers 58 and 58, the unit continues to revolve until lever arm 58 causes the disengagement of pawl 51 with one of the ratchet teeth 41, at which time gear 48 continues to revolve, shaft 48 and parts 58, 5|, 58, 58, 51, 8|, 58 and 58 (see Fig. 7) remain stationary, held from revolving with gear 48 because pawl levers 58 and 58 have been stopped by obstruction 44 and held from revolving or creeping in the reverse direction under the reactive forces of frictional drag 5| pressed against gear 48 by the spring 58. Ratchet wheel r 55 and pinion 58 are left free on shaft 48 to revolve in either direction. The members 48, 58, 5|, 58, 58, 51, 58 and 58 constitute what may be termed an intermediate floating mechanism.-

A manual control device for the projecting member 44 is shown in Fig. 8 of the drawings and includes a cylinder 1| operatively associated with the gear box 22 and secured thereto as by means of flange 12 and a plurality of bolts 18. A piston 14 is mounted on an extension of member 44,

which extension may constitute a piston rod 15. A spring 11 biases the piston assembly and the obstacle 44 to the position shown in the drawings. A bulb 18 is operatively connected to the cylinder 1| by a flexible hose 18 in such manner as to counteract the bias caused by the spring 11. When the bulb 18 is compressed by an operator using either the hand, knee or foot, the piston and the projection 44 are moved upwardly or away from the member 22 so that the obstacle 44 will be moved out of engagement with the clutch in the same manner as has been set forth for the electromagnetic actuator.

I have shown another form of manual control in Fig. 9, including a wire 8| freely movable in a hose 82. A compression spring 88 biases the projection 44 to its outward position where it may engage lever arms 58 and 88 to cause a disengagement of the clutch; A small casing 84 has a foot-operated lever 88 pivotally mounted therein, a spring 81 biasing the lever to a predetermined position. The wire 8| is connected to the lever 88. An actuating knob 88 on a push rod 89 permits of moving the lever against the spring 81, so that pressure on the knob effects movement of the obstacle 44 out of the path of travel of lever arms 58 and 88 of the clutch in substantially the same manner as was hereinbefore mentioned for the electromagnetic control.

The lever arms and pawls work independently in engaging except that in engaging, pawl 51 always engages ratchet teeth 41 a trifle before its mate arm engages (see the overlapping shape of pawl lever 58), and upon disengaging, lever arm 58 strikes obstacle 44 first and disengages pawl 59 from ratchet wheel 55 a trifle in advance of the disengagement of its mating pawl arm. This appears to be necessary for smooth operation.

In operating clutches with alternating-current magnets, the difliculty heretofore has been that where much load is placed on the magnet the armature will chatter and be noisy. In my application, the work done by the magnet is a minimum. The clutch is normally energized and the actual work of disengaging the clutch is done by the momentum of the parts, when the magnet is inoperative because it is deenergized and the work of engaging the clutch is irrespective of the magnet. Should the current source fail the clutch will be automatically disengaged because the rotating parts have sufllcient momentum to cause their disengagement when obstructed.

While I have shown a specific embodiment of my invention and as applied to an ironer, I do not desire to be limited to the particular details shown as the scope of the claims is to be limited only by the prior art;

I claim as my invention:

1. In a clutch, in combination, a loosely mounted shaft, a drivinggear loosely supported on the shaft and having internal ratchet teeth, a driven gear having external ratchet teeth loosely mounted on the shaft, a disc fixed on the shaft between said driven and driving gears, a pair of arms, pivotally mounted on the disc at the respective sides thereof, each arm having a pawl thereon adapted to engage with and be disengaged from the respective internal and external ratchet teeth and a single spring carried by the disc tending to hold the pawls in engagement with the cooperating ratchet teeth.

2. In a clutch, in combination, a loosely mounted shaft, a driving gear loosely supported on the shaft and having internal ratchet teeth, a driven gear having external ratchet teeth associated therewith loosely mounted on the shaft, ,a disc fixed on the shaft between the drivenand the driving gear, a pair of pawl arms pivotally mounted on the disc at the opposite sides thereof and adapted to engage the ratchet teeth to transmit motion from the driving gear-to the driven gear, resilient means carried by the disc to yieldingly urge the pawl arms into engagement with the respective ratchet teeth and means movable into the path of movement of the pawl arms to cause disengagement of the pawl arms and the ratchet teeth.

3. A device as set forth in claim 2 and including a friction disc on the shaft interlocked with the fixed disc and spring pressed against the driving gear to prevent creeping of the clutch when the pawl arms are out of engagement with the respective ratchet teeth.

., 4. A device as set forth inclailn 2 and including a friction disc loosely mountedon the shaft and located between the driving gear and the fixed disc, a lug on the friction disc extending into the fixed disc and a spring surrounding the shaft between the friction disc and the fixed disc to press the friction disc against the driving gear to prevent reverse turning movement of the clutch when the pawl arms are out of engagement with the respective ratchet teeth. v

5. A deviceas set forth in claim 2 in which the pawl-arm-disengaging means includes a radiallymovable obstacle.

6. A device as set forth in claim 2 in which the pawl-arm-disengaging means includes a manually-controlled radially-movable obstacle.

7. A device as set forth in claim 2 in which the pawl-arm-disengaging means includes an obstacle adapted to move into the path of travel of both pawl arms and engage them in predetermined sequence.

8. A device as set forth in claim 2 in which the pawl-arm-disengaging means includes an obstacle yieldingly pressed into the path of travel of both pawl arms and manually-controlled means to move the obstacle out of thepath of 1 travel.

WILLIAM M. EMERY. 

